Non-mendelial female sterility in Drosophila melanogaster: demonstration of an inducer chromosome 4]

Crosses between two classes of Drosophila melanogaster strains (reactive and inducer) may lead to partially sterile F1 females. This sterility, called S.F. sterility, can be characterized by its physiological features. It appears to be the result of an interaction between two factors: "R" brought into the initial croos by the reactive mother and "I" by chromosomes of the inducer father. Except for chromosome 4, each chromosome of the well known inducer strains may carry the I factor (inducer chromosomes). The present results provide evidence for the presence of an inducer fourth chromosome in the inducer strain Nagasaki.     

Enzymes of Sphingolipid metabolism in Drosophila melanogaster

Sphingolipids are important structural components of membranes that delimit the boundaries of cellular compartments, cells and organisms. They play an equally important role as second messengers, and transduce signals across or within the compartments they define to initiate physiological changes during development, differentiation and a host of other cellular events. For well over a century Drosophila melanogaster has served as a useful model organism to understand some of the fundamental tenets of development, differentiation and signaling in eukaryotic organisms. Directed approaches to study sphingolipid biology in Drosophila have been initiated only recently. Nevertheless, earlier phenotypic studies conducted on genes of unknown biochemical function have recently been recognized as mutants of enzymes of sphingolipid metabolism. Genome sequencing and annotation have aided the identification of homologs of recently discovered genes. Here we present an overview of studies on enzymes of the de novo sphingolipid biosynthetic pathway, known mutants and their phenotypic characterization in Drosophila.Received 14 June 2004; received after revision 15 August 2004; accepted 21 August 2004     

Inbreeding effect: embryonic development and fecundity of Drosophila melanogaster offspring.

Inbreeding depression observed on fecundity of adult Drosophila depends on the effect observed during development of the eggs laid by their parents. This depression does not then depend on the homozygosity per se of the adult genome. It is mainly due to the deleterious effect observed primarily during embryogenesis.     

Involution of genital function with age studied as an index aging in Drosophila melanogaster]

Reproductive system in Drosophila estimated by fertility in female and fertilizing power in male gradually decreased with age. Physiological changes as a function of age occur slowly in virgin females and their ageing seems really slower than those observed in inseminated ones. On the other hand, genital function involution is the same in virgin and mated males and seems independent of aging.     

Effect of hyperthermia upon gamma-ray induced crossing-over in an excision repair deficient male Drosophila melanogaster

Hyperthermia of 1 h at 38 degrees C did increase gamma-ray induced crossing-over in meiotic cells of male larvae and adults. However, there was considerably less effect of the heat treatment upon radiation induced crossing-over (a chromosome breakage event) in an excision repair mutant y mei-9a.